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A Periphery ported side exhaust is better than both intake and exhaust being periphery ported. Neither the intake or exhaust port ever closes. So, there is exhaust dilution of the intake flow based on the amount of exhaust back pressure. Up to the point where RPMs do not allow enough time for this to occur.Then it sort of steps up on the cam and the power comes on as if by an electric switch. The full periphery engine tunes like a dirt bike. The intake length and diameter and the exhaust length and diameter tune like a trombone.
A periphery ported 12-A can do 310 HP at 10,000 RPM. A 13-B can do 330 HP at 10,000 RPM. We have to be under 105Db at 50 feet at full throttle. The Renesis has zero overlap. But it had a Micky Mouse intake with 2 different tuned lengths.
There was a builder at Sun&Fun years ago who had a RX-7 transmission for speed reduction. It worked fine. Later he had the idle too slow and it shook the gears of of 2nd gear. I forgot his name but he died of cancer.
LEH
In a message dated 10/20/2020 5:35:49 PM Atlantic Standard Time, flyrotary@lancaironline.net writes:
Mat,
It will only idle hot at that rpm. (1800). Cold it is 2000 plus. Yes P ported and the advance seems to vary little from 20 degrees. Running Fueltech ECU. And running cheapest gas.
Neil.
From: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Wednesday, October 21, 2020 1:38 AM
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Subject: [FlyRotary] Re: Tuning
Steve = Using Megasquirt for ECU. How is your flight testing going?
Jeff = I meant prop rpm. Using Neil's PSRU, which is 3.17. I just bumped up my idle to around 800prop (2500engine). I forgot to add, I am P-Port which causes a need for higher idle.
Lynn = Idle can be that high? Usually I see rotary idle around the 10-18 range, but that is for a car. Little different with a prop on 100% of the time.
Neil = That is a nice idle. I forget, are you P-Port? What is your timing at?
Dave = 35 all time? Doesn't that seem really high for rotary. Pump gas? Lynn was saying 24 degrees for 87 octane.
Hi there Matt and all
What computer is controlling your fuel and spark Matt?
Ive left the timing of the EC2 on the Renesis 4 port at Tracy’s default and haven’t changed it but was wanting to do some experimenting.
I take it that the timing setting in the EC2/3 will vary the whole timing curve over the rpm/load envelope.
Cheers
Steve Izett
Renesis 4 port EC2 EM3 RD1-C
> On 19 Oct 2020, at 10:21 am, Matt Boiteau mattboiteau@gmail.com <flyrotary@lancaironline.net> wrote:
>
> Split table.
>
> - Matt Boiteau
>
>
> On Sun, Oct 18, 2020 at 10:17 PM Matt Boiteau mattboiteau@gmail.com <flyrotary@lancaironline.net> wrote:
>
> What AFR and timing are people running for idle, taxi, takeoff, climb, cruise, descent?
>
> idle = 11afr, 20 timing
> I seem to have to be around 11afr for it to stay alive. Still trying to get it to idle around 600rpm, maybe bump it up to 700rpm to be smoother without dieing and shaking apart.
>
> taxi / takeoff / climb = 13.2afr, 28 timing
>
> cruise - not sure aft, 28 timing
>
> decent - not sure aft, 32 timing
> Not sure what the plane likes. I tried 14afr, but the MAP really get's low and engine shakes. Guessing it should be more rich?
>
> I attached the timing table and split rotary table (second email). Not sure how to tune timing, I just want safe values for now.
>
>
> - Matt Boiteau
> --
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